Comorbidity of autistic spectrum disorders in children with Down syndrome

Abstract

The aim of the study was to identify the comorbidity of autistic spectrum disorders in a population of children with Down syndrome (DS). All children with DS within a defined population of South Birmingham were identified. The Asperger Syndrome Screening Questionnaire and the Child Autism Rating Scale were completed and diagnosis made according to ICD‐10 criteria following interview and observation. Thirty‐three of 58 identified children completed the measures, four of whom received a diagnosis of an autistic spectrum disorder. This is equivalent to a minimum comorbid rate of 7%. The questionnaire items concerning social withdrawal, restricted or repetitive interests, clumsiness, and unusual eye contact were associated with an autistic disorder. Of the remaining 29 participating children, 11 also displayed marked obsessional and ritualistic behaviours. The comorbid occurrence of autism and DS is at least 7%. It is important that these children are identified and receive appropriate education and support. A full assessment of social, language, and communication skills and behaviour is crucial, particularly in children with DS who appear different from other children with DS. Potential mechanisms accounting for this comorbidity are discussed.

Prevalence of Pervasive Developmental Disorder in Down’s Syndrome

“…This study, with a small sample size, found a frequency of 7% of PDD in DS (Kent et al, 1999). Our result is more than twofold higher than this previous study, maybe due to methodological issues, such as the screening proprieties of ASQ and/or sample size.…”

“…Our result is more than twofold higher than this previous study, maybe due to methodological issues, such as the screening proprieties of ASQ and/or sample size. Despite these differences, one might assume that DS is a risk factor for PDD, since the frequencies found in other mental retardation tend to be lower (Capone et al, 2005;Kent et al, 1999). Interestingly, like previous studies (Fombonne, Zakarian, Bennett, Meng, & Mclean-Heywood, 2006), we found no gender differences between groups suggesting that higher male prevalence found in PDD is lacking in DS population.…”

“…The frequencies of pervasive developmental disorder (PDD) in Down's syndrome (DS) have been reported from 1% to 11% (Capone, Grados, Kaufmann, Bernard-Ripol, & Jewel, 2005;Kent, Ivans, Paul, & Sharp, 1999;Lund, 1988). However, it is not clear if the frequency of this co-occurrence is higher or lower than in other mental retardations.…”

Brief Report: Autism in Individuals with Down Syndrome

“…Although there have been few reports of autism in individuals with Down syndrome, studies have suggested that the association may be more common than generally thought (Ghaziuddin, Tsai, & Ghaziuddin, 1992;Howlin, Wing, & Gould, 1995;Kent, Evans, Paul, & Sharp, 1999;Kent, Perry, & Evans, 1998). Ghaziuddin et al (1992) estimated that for every 100 persons with Down syndrome, 4 or 5 may also have autism.…”

“…Ghaziuddin et al (1992) estimated that for every 100 persons with Down syndrome, 4 or 5 may also have autism. Rates of autism have ranged across studies from 1 to 11% of the sample depending on the study, its methodology and the autism criteria used (Collacott, Cooper, & McGrother, 1992;Gath & Gumley, 1986;Kent et al, 1999;Myers & Pueschel, 1991). Kent et al (1999) found that 4 of 58 children with Down syndrome between the ages of 6 and 9 met ICD-10 criteria for autism, a rate of 7%.…”